Yeah, I'm almost positive that this is a Colt Detective Special.
Webley Mk VI
Blofeld (Donald Pleasance) drops a Webley Mk VI, which one of his henchmen had handed him, in the volcano lair when Tiger throws a star into his arm. Bond picks it up and uses it during the assault on the volcano lair. Kissy (Mie Hama) also briefly uses one to kill one of Blofeld's guards that takes away Tiger's gun.
MP40
The SPECTRE guards in the volcano use MP40s. Tiger Tanaka (Tetsuro Tamba) also picks one up and fires it after Bond kills the guard using it.
Star Z-45
Tiger's Ninjas use the Star Z-45 SMG when in the volcano crater. (These scenes were filmed in Spain, explaining the Star's presence. Once the action shifts to the volcano interior, these SMGs are not seen again.)
Sterling L2A3
A Sterling L2A3 is used by Chinese hitmen during Bond's "murder" in Hong Kong during the pre-credits sequence. They are also used by Tiger's Ninjas and SPECTRE guards during the final battle.
Thompson M1A1
An assassin trying to kill Bond in Tokyo carries a Thompson M1A1.
Lee-Enfield No. 4
A Royal Navy honor guard uses the Lee-Enfield No. 4 during Bond's Hong Kong "funeral".